Proffessor Griff, a former member of the Grammy-winning rap group Public Enemy, is caught up in some controversy surrounding the lone shooter of the Dallas police shooting that happened during a peace rally on Thursday night (July 7).

During a press conference Friday afternoon (July 8), Dallas Police Chief David O. Brown identified the gunman as Micah Xavier Johnson, a US Army reservist who died during a standoff with police.

According to USA Today, when investigators combed through Johnson’s Facebook page, which has since been deactivated, they discovered a selfie taken with Richard “Professor Griff” Griffin, 55, which has since been distributed by media outlets. In addition, Brown told the media that Johnson also studied Griffin’s audiobook, A Warriors Tapestry.

Since the news broke, Griff has been on a campaign via social media to distance himself from the shooter. In a series of tweets, the 55-year-old denied any links to Johnson and claims that the police and FBI are tapping his phones.

“I do not advocate killing Cops,” he tweeted, adding, “The police and FBI have been watching me and tapping my phone they know who I talk too, I DO NOT KNOW THE SHOOTER.”